This allows gdb to access the target’s auxiliary vector,
which can be helpful for telling system libraries important details
about the hardware, operating system, and process.
Signed-off-by: Lirong Yuan <yua...@google.com>
---
Changelog since v1:
- Added a multiarch gdbstub test to verify this is working properly.
---
gdbstub.c | 54 ++++++++++++++++
tests/tcg/multiarch/Makefile.target | 9 ++-
.../multiarch/gdbstub/test-qxfer-auxv-read.py | 64 +++++++++++++++++++
3 files changed, 126 insertions(+), 1 deletion(-)
create mode 100644 tests/tcg/multiarch/gdbstub/test-qxfer-auxv-read.py
diff --git a/gdbstub.c b/gdbstub.c
index f3a318cd7f..e1e1a2c1e6 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -2124,6 +2124,12 @@ static void handle_query_supported(GdbCmdContext
*gdb_ctx, void *user_ctx)
g_string_append(gdbserver_state.str_buf, ";qXfer:features:read+");
}
+#ifdef CONFIG_USER_ONLY
+ if (gdbserver_state.c_cpu->opaque) {
+ g_string_append(gdbserver_state.str_buf, ";qXfer:auxv:read+");
+ }
+#endif
+
if (gdb_ctx->num_params &&
strstr(gdb_ctx->params[0].data, "multiprocess+")) {
gdbserver_state.multiprocess = true;
@@ -2185,6 +2191,46 @@ static void handle_query_xfer_features(GdbCmdContext
*gdb_ctx, void *user_ctx)
gdbserver_state.str_buf->len, true);
}
+#ifdef CONFIG_USER_ONLY
+static void handle_query_xfer_auxv(GdbCmdContext *gdb_ctx, void *user_ctx)
+{
+ TaskState *ts;
+ unsigned long offset, len, saved_auxv, auxv_len;
+ const char *mem;
+
+ if (gdb_ctx->num_params < 2) {
+ put_packet("E22");
+ return;
+ }
+
+ offset = gdb_ctx->params[0].val_ul;
+ len = gdb_ctx->params[1].val_ul;
+ ts = gdbserver_state.c_cpu->opaque;
+ saved_auxv = ts->info->saved_auxv;
+ auxv_len = ts->info->auxv_len;
+ mem = (const char *)(saved_auxv + offset);
+ if (offset > auxv_len) {
+ put_packet("E00");
+ return;
+ }
+
+ if (len > (MAX_PACKET_LENGTH - 5) / 2) {
+ len = (MAX_PACKET_LENGTH - 5) / 2;
+ }
+
+ if (len < auxv_len - offset) {
+ g_string_assign(gdbserver_state.str_buf, "m");
+ memtox(gdbserver_state.str_buf, mem, len);
+ } else {
+ g_string_assign(gdbserver_state.str_buf, "l");
+ memtox(gdbserver_state.str_buf, mem, auxv_len - offset);
+ }
+
+ put_packet_binary(gdbserver_state.str_buf->str,
+ gdbserver_state.str_buf->len, true);
+}
+#endif
+
static void handle_query_attached(GdbCmdContext *gdb_ctx, void *user_ctx)
{
put_packet(GDB_ATTACHED);
@@ -2290,6 +2336,14 @@ static GdbCmdParseEntry gdb_gen_query_table[] = {
.cmd_startswith = 1,
.schema = "s:l,l0"
},
+#ifdef CONFIG_USER_ONLY
+ {
+ .handler = handle_query_xfer_auxv,
+ .cmd = "Xfer:auxv:read::",
+ .cmd_startswith = 1,
+ .schema = "l,l0"
+ },
+#endif
{
.handler = handle_query_attached,
.cmd = "Attached:",
diff --git a/tests/tcg/multiarch/Makefile.target
b/tests/tcg/multiarch/Makefile.target
index cb49cc9ccb..c8cdb1e04d 100644
--- a/tests/tcg/multiarch/Makefile.target
+++ b/tests/tcg/multiarch/Makefile.target
@@ -54,7 +54,14 @@ run-gdbstub-sha1: sha1
--bin $< --test $(MULTIARCH_SRC)/gdbstub/sha1.py, \
"basic gdbstub support")
-EXTRA_RUNS += run-gdbstub-sha1
+run-gdbstub-qxfer-auxv-read: sha1
+ $(call run-test, $@, $(GDB_SCRIPT) \
+ --gdb $(HAVE_GDB_BIN) \
+ --qemu $(QEMU) --qargs "$(QEMU_OPTS)" \
+ --bin $< --test
$(MULTIARCH_SRC)/gdbstub/test-qxfer-auxv-read.py, \
+ "basic gdbstub qXfer:auxv:read support")
+
+EXTRA_RUNS += run-gdbstub-sha1 run-gdbstub-qxfer-auxv-read
endif
diff --git a/tests/tcg/multiarch/gdbstub/test-qxfer-auxv-read.py
b/tests/tcg/multiarch/gdbstub/test-qxfer-auxv-read.py
new file mode 100644
index 0000000000..88049dd330
--- /dev/null
+++ b/tests/tcg/multiarch/gdbstub/test-qxfer-auxv-read.py
@@ -0,0 +1,64 @@
+from __future__ import print_function
+#
+# Test the SVE ZReg reports the right amount of data. It uses the
+from __future__ import print_function
+#
+# Test auxiliary vector is loaded via gdbstub
+#
+# This is launched via tests/guest-debug/run-test.py
+#
+
+import gdb
+import sys
+
+failcount = 0
+
+def report(cond, msg):
+ "Report success/fail of test"
+ if cond:
+ print ("PASS: %s" % (msg))
+ else:
+ print ("FAIL: %s" % (msg))
+ global failcount
+ failcount += 1
+
+def run_test():
+ "Run through the tests one by one"
+
+ cond = True
+ try:
+ gdb.execute("info auxv")
+ except (gdb.error, AttributeError):
+ cond = False
+
+ report(cond, "Display the auxiliary vector of the inferior.")
+
+#
+# This runs as the script it sourced (via -x, via run-test.py)
+#
+try:
+ inferior = gdb.selected_inferior()
+ arch = inferior.architecture()
+ print("ATTACHED: %s" % arch.name())
+except (gdb.error, AttributeError):
+ print("SKIPPING (not connected)", file=sys.stderr)
+ exit(0)
+
+if gdb.parse_and_eval('$pc') == 0:
+ print("SKIP: PC not set")
+ exit(0)
+
+try:
+ # These are not very useful in scripts
+ gdb.execute("set pagination off")
+ gdb.execute("set confirm off")
+
+ # Run the actual tests
+ run_test()
+except (gdb.error):
+ print ("GDB Exception: %s" % (sys.exc_info()[0]))
+ failcount += 1
+ pass
+
+print("All tests complete: %d failures" % failcount)
+exit(failcount)
--
2.28.0.163.g6104cc2f0b6-goog
